From 19785f43d18891307dd18c1ed33b21099848ca72 Mon Sep 17 00:00:00 2001 From: ksss Date: Wed, 14 Jun 2017 17:07:32 +0900 Subject: Reimplement String#upto --- mrbgems/mruby-string-ext/src/string.c | 114 ++++++++++++++++++++++++++++++++++ 1 file changed, 114 insertions(+) (limited to 'mrbgems/mruby-string-ext/src/string.c') diff --git a/mrbgems/mruby-string-ext/src/string.c b/mrbgems/mruby-string-ext/src/string.c index 9dc1aeafc..4740b356f 100644 --- a/mrbgems/mruby-string-ext/src/string.c +++ b/mrbgems/mruby-string-ext/src/string.c @@ -521,6 +521,119 @@ mrb_str_ord(mrb_state* mrb, mrb_value str) } #endif +static mrb_bool +all_digits_p(const char *s, mrb_int len) +{ + while (len-- > 0) { + if (!ISDIGIT(*s)) return FALSE; + s++; + } + return TRUE; +} + +/* + * call-seq: + * str.upto(other_str, exclusive=false) {|s| block } -> str + * str.upto(other_str, exclusive=false) -> an_enumerator + * + * Iterates through successive values, starting at str and + * ending at other_str inclusive, passing each value in turn to + * the block. The String#succ method is used to generate + * each value. If optional second argument exclusive is omitted or is false, + * the last value will be included; otherwise it will be excluded. + * + * If no block is given, an enumerator is returned instead. + * + * "a8".upto("b6") {|s| print s, ' ' } + * for s in "a8".."b6" + * print s, ' ' + * end + * + * produces: + * + * a8 a9 b0 b1 b2 b3 b4 b5 b6 + * a8 a9 b0 b1 b2 b3 b4 b5 b6 + * + * If str and other_str contains only ascii numeric characters, + * both are recognized as decimal numbers. In addition, the width of + * string (e.g. leading zeros) is handled appropriately. + * + * "9".upto("11").to_a #=> ["9", "10", "11"] + * "25".upto("5").to_a #=> [] + * "07".upto("11").to_a #=> ["07", "08", "09", "10", "11"] + */ +static mrb_value +mrb_str_upto(mrb_state *mrb, mrb_value beg) +{ + mrb_value end; + mrb_value exclusive = mrb_false_value(); + mrb_value block = mrb_nil_value(); + mrb_value current, after_end; + mrb_int n; + mrb_bool excl; + + mrb_get_args(mrb, "o|o&", &end, &exclusive, &block); + + if (mrb_nil_p(block)) { + return mrb_funcall(mrb, beg, "to_enum", 3, mrb_symbol_value(mrb_intern_lit(mrb, "upto")), end, exclusive); + } + end = mrb_string_type(mrb, end); + excl = mrb_test(exclusive); + + /* single character */ + if (RSTRING_LEN(beg) == 1 && RSTRING_LEN(end) == 1 && + ISASCII(RSTRING_PTR(beg)[0]) && ISASCII(RSTRING_PTR(end)[0])) { + char c = RSTRING_PTR(beg)[0]; + char e = RSTRING_PTR(end)[0]; + + if (c > e || (excl && c == e)) return beg; + for (;;) { + mrb_yield(mrb, block, mrb_str_new(mrb, &c, 1)); + if (!excl && c == e) break; + c++; + if (excl && c == e) break; + } + return beg; + } + /* both edges are all digits */ + if (ISDIGIT(RSTRING_PTR(beg)[0]) && ISDIGIT(RSTRING_PTR(end)[0]) && + all_digits_p(RSTRING_PTR(beg), RSTRING_LEN(beg)) && + all_digits_p(RSTRING_PTR(end), RSTRING_LEN(end))) { + mrb_int min_width = RSTRING_LEN(beg); + mrb_int max_width = RSTRING_LEN(end); + mrb_int bi = mrb_int(mrb, mrb_str_to_inum(mrb, beg, 10, FALSE)); + mrb_int ei = mrb_int(mrb, mrb_str_to_inum(mrb, end, 10, FALSE)); + char buf[max_width+1]; + + while (bi <= ei) { + if (excl && bi == ei) break; + snprintf(buf, sizeof(buf), "%.*d", min_width, bi); + mrb_yield(mrb, block, mrb_str_new(mrb, buf, strlen(buf))); + bi++; + } + return beg; + } + /* normal case */ + n = mrb_int(mrb, mrb_funcall(mrb, beg, "<=>", 1, end)); + if (n > 0 || (excl && n == 0)) return beg; + + after_end = mrb_funcall(mrb, end, "succ", 0); + current = mrb_str_dup(mrb, beg); + while (!mrb_str_equal(mrb, current, after_end)) { + mrb_value next = mrb_nil_value(); + if (excl || !mrb_str_equal(mrb, current, end)) + next = mrb_funcall(mrb, current, "succ", 0); + mrb_yield(mrb, block, current); + if (mrb_nil_p(next)) break; + current = mrb_str_to_str(mrb, next); + if (excl && mrb_str_equal(mrb, current, end)) break; + if (RSTRING_LEN(current) > RSTRING_LEN(end) || RSTRING_LEN(current) == 0) + break; + } + + return beg; +} + void mrb_mruby_string_ext_gem_init(mrb_state* mrb) { @@ -545,6 +658,7 @@ mrb_mruby_string_ext_gem_init(mrb_state* mrb) mrb_alias_method(mrb, s, mrb_intern_lit(mrb, "next"), mrb_intern_lit(mrb, "succ")); mrb_alias_method(mrb, s, mrb_intern_lit(mrb, "next!"), mrb_intern_lit(mrb, "succ!")); mrb_define_method(mrb, s, "ord", mrb_str_ord, MRB_ARGS_NONE()); + mrb_define_method(mrb, s, "upto", mrb_str_upto, MRB_ARGS_ANY()); mrb_define_method(mrb, mrb->fixnum_class, "chr", mrb_fixnum_chr, MRB_ARGS_NONE()); } -- cgit v1.2.3